Several known moulding methods by impregnation of fibres with resin may be used for making parts in composite material and notably moulding methods using closed moulds.
Firstly, mention may be made of the resin-transfer moulding or RTM method.
In this RTM method, a set of fibre elements is positioned in a particular way around a support and the set is placed inside a closed mould, the general shape of which corresponds to that of the part to be made.
In the traditional RTM method, this mould consists of a female mould or matrix and a counter-mould portion or punch.
A resin is then injected into the mould and polymerised by providing energy to it. The molecules of this resin then begin to bind together and form a solid network. A rigid part in composite material formed with fibres and polymerised resin is then obtained.
Mention may also be made of the resin infusion moulding method.
Generally, such a method applies several steps among which appears the placement of fibre reinforcing elements on the shape of a mould.
The mould is then closed via a flexible lid allowing controlled passage of a resin which will infuse inside the fibre reinforcing elements and then polymerise, in order to provide a rigid part.
The propagation of the resin is accomplished by a driving force generated by a depression in certain points of the lid, towards which moves the resin introduced into the mould.
In the traditional infusion method, moulding tooling is thus formed with a matrix mould and a sealed lid such as a cover as a counter-mould portion.
These methods whether these are standard RTM or resin infusion moulding methods, are technologies in which the moulding tooling is heavy and designed for a specific part shape intended to be made. This generates high tooling costs in order to be able to produce very diverse parts.
Further, this tooling may have a very limited lifetime. Indeed, it is understood that in standard RTM tooling, deterioration of the matrix mould or of the counter-mould or of both of them involves deterioration of the thereby formed tooling in its entirety.
Finally, because of the complex development of moulding tooling adapted to a specific type of part in a composite material, these technologies are limited to shapes of parts in composite material which are not very or moderately complex, the characteristics of which are not very elaborated.